Evaporation occurs in many areas of air conditioning and refrigeration engineering and in process and energy engineering. Shell and tube heat exchangers are often used in this type of engineering, in which exchangers liquids from pure substances or mixtures evaporate on the outside of the tube, and thereby cool off a brine or water on the inside of the tube. Such devices are identified as flooded evaporators.
By intensifying the heat transfer on the outside and the inside of the tube, it is possible to significantly reduce the size of the evaporator. This reduces the manufacturing costs of such devices. Furthermore the required filling capacity of refrigerant is reduced which, in the case of the current predominantly used HFCs, can amount to a significant portion of the entire cost of the system. Furthermore, the potential of danger can be reduced, in the case of toxic or flammable refrigerants, by a reduction of the filling capacity. The current common double enhanced tubes are more efficient by approximately a factor of three than plain tubes with the same diameter.